An anatomical view of a human stomach S and associated features is shown in FIG. 1A. The esophagus E delivers food from the mouth to the proximal portion of the stomach S. The z-line or gastro-esophageal junction Z is the irregularly-shaped border between the thin tissue of the esophagus and the thicker tissue of the stomach wall. The gastro-esophageal junction region G is the region encompassing the distal portion of the esophagus E, the z-line, and the proximal portion of the stomach S.
Stomach S includes a fundus F at its proximal end and an antrum A at its distal end. Antrum A feeds into the pylorus P which attaches to the duodenum D, the proximal region of the small intestine. Within the pylorus P is a sphincter that prevents backflow of food from the duodenum D into the stomach. The middle region of the small intestine, positioned 30 distally of the duodenum D, is the jejunum J.
FIG. 1B illustrates the tissue layers forming the stomach wall. The outermost layer is the serosal layer or “serosa” S and the innermost layer, lining the stomach interior, is the mucosal layer or “mucosa” MUC. The submucosa SM and the multi-layer muscularis M lie between the mucosa and the serosa.
Prior applications, including WO 2005/037152 (incorporated herein by reference in its entirety) describe methods according to which medical implants are coupled to tissue structures formed within the stomach. According to these applications, devices for inducing weight loss (e.g. by restricting and/or obstructing flow of food into the stomach, and/or by occupying a portion of the stomach volume) may be coupled to tissue tunnels or plications P (FIG. 2) formed from stomach tissue.
For example, U.S. application Ser. No. 11/439,461, Filed May 23, 2006, (incorporated herein by reference in its entirety), describes a Restrictive and/Or Obstructive Implant System for Inducing Weight Loss. In one embodiment, flexible loops 2 (FIG. 3) are coupled to tissue plications P (FIG. 2) formed in the gastroesophageal junction region of the stomach. An implant, such as a flow restrictive and/or obstructive implant 4 (FIG. 4), is passed through the loops 2 and thus retained in the stomach as shown in FIG. 5.
U.S. application Ser. No. 11/542,457, filed Oct. 3, 2006 discloses other implants, including a restrictive pouch having anchors extending from its outer surface. During implantation, the anchors are inserted to cutouts/holes formed in plicated tissue.
In other instances, tissue plications may themselves be sufficient to provide the necessary treatment. For example, the plications may be used to reduce stomach volume or form a flow restriction within the stomach. Two or more plications may be drawn together and retained in some way, such as to form a restriction and/or reduce stomach volume, as also described in U.S. application Ser. No. 11/542,457, filed Oct. 3, 2006.
Other types of implants may be coupled to such plications or other tissue structures for a variety of purposes. These implants include, but are not limited to gastric space occupiers, prosthetic valves for the treatment of gastro-esophageal reflux disease, gastric stimulators, pH monitors and drug eluting devices that release drugs, biologies or cells into the stomach or elsewhere in the GI tract. Such drug eluting devices might include those which release leptin (a hormone which creates feelings of satiety), Ghrelin (a hormone which creates feelings of hunger), octreotide (which reduces Ghrelin levels and thus reduces hunger), Insulin, chemotherapeutic agents, natural biologics (e.g. growth factor, cytokines) which aid is post surgery trauma, ulcers, lacerations etc. Still other implants might be of a type which might provide a platform to which specific cell types can adhere, grow and provide biologically-active gene products to the GI tract, and/or a platform for radiation sources that can provide a local source of radiation for therapeutic purposes, or provide a platform whereby diagnostic ligands are immobilized and used to sample the GI tract for evidence of specific normal or pathological conditions, or provide an anchor point for imaging the GI tract via cameras and other image collecting devices.
Prior applications listed above address the desirability of forming tissue plications, pockets or tunnels in a way that regions of serosal tissue (i.e. the tissue on the exterior surface of the stomach) are retained in contact with one another. Over time, adhesions formed between the opposed serosal layers create strong bonds that can maintain the plication over extended durations, despite the forces imparted on them by abdominal movement and implanted devices. More durable plications can be created by placing any of a number of materials and/or substances (e.g. injectable sclerosing agents) between the serosal surfaces prior to plicating the serosal surfaces together. One example of material suitable for this purpose is polypropolyene mesh, commonly used for hernia repair, which when inserted in the plication fold provides a durable anchoring position within the GI tract.
Regardless of the application for which a plication is being formed, it is highly desirable to form that plication using steps carried out from within the stomach using instruments passed down the esophagus, rather than using more invasive surgical or laparoscopic methods.
The present application describes endoscopic plicators which may be passed transorally into the stomach and used to plicate stomach tissue by engaging tissue from inside of the stomach and drawing it inwardly. A section of stomach wall tissue drawn inwardly will be referred herein as a “pinch” of tissue, although it may be drawn inwardly using suction or other means. In preferred embodiments, a retracting component draws tissue into the path of travel of a stapler head. Vacuum and/or mechanical retractors may be used for retraction. By drawing a portion of the stomach wall between the stapler head and anvil, the retracting component causes sections of serosal tissue on the exterior of the stomach to be positioned facing one another. The disclosed plicators deliver staples to secure the opposed sections of tissue to one another, but instead may deliver sutures or other means for maintaining contact between the tissue sections at least until serosal bonds form between them. The plicator may pass a mesh element and/or sclerosing agent through the stomach wall into position between the opposed regions of serosal tissue thus enhancing serosal bonding. Each of these steps may be performed wholly from the inside of the stomach and thus can eliminate the need for any surgical or laparoscopic intervention. Medical devices may then be attached to the anchor for retention within the stomach.
While this application describes plication systems and methods with respect to the formation of plications is stomach tissue, the embodiments described herein have equal applicability for forming plications in parts of the body within or outside the GI system.